Hey!
I am really sorry to hear that - I know how discouraging those feedback calls can feel, especially after putting so much effort in. However, from what you have said, it doesn't sound like you were "bad" across the board at all! Scoring well on one question shows that you absolutely have the strengths and skills that they recognised, and "average" in a competitive VS process often means you were still performing at a good level.
Sometimes these interviews can come down to a few answers being slightly stronger or more tailored on the day, rather than your overall potential or ability to succeed in law. The fact that you were able to get detailed feedback is really valuable as it gives you something concrete to work on for next time.
I also think that we sometimes underestimate how much nerves can impact performance in these processes. I found that once I became more familiar with interviews and assessments and started feeling a bit more confident, my performance improved a lot naturally. These things really do get a lot easier with practice, and it is always important to remind yourself that you wouldn't be making it to the later stages in the process if the firm didn't think you were capable.
I appreciate it feels personal right now, but one interview results really doesn't define your capabilities. A lot of people who go on to secure VSs and TCs have several rejections and disappointing feedback calls before things click (+ I received far more rejections than I can count!), so it is all about being resilient and focusing on the areas that you feel less confident in.
Wishing you the best of luck - you have TCLA rooting for you!!